When you think of aquatic mammals, do
you think of a whale or an otter? In truth, there are a number of
mammals who rely on water for hunting and fishing, as well as those
who spend their entire lives in the sea. Although they may look
like fish, dolphins and whales are in fact mammals -- they are warm
blooded, have very fine hairs on their bodies, and produce milk
to feed their young. While they never emerge from the water, however,
other sea mammals like seals and sea lions divide their time equally
between water and land, using it for both for fishing and for fun.

Whales in captivity which were captured from different
oceans often suffer "culture shock" when forced to share
an enclosure. Scientists believe that, just like people, whales from
different parts of the world speak their own language, so that animals
of the same species can't understand each other.